1. Field
Embodiments of the present invention generally relate to a magnetic write head for use in a hard disk drive.
2. Description of the Related Art
The heart of a computer is a magnetic disk drive which typically includes a rotating magnetic media, such as a disk, a slider that has read and write heads, a suspension arm above the rotating disk and an actuator arm that swings the suspension arm to place the read and/or write heads over selected circular tracks on the rotating disk. The suspension arm biases the slider towards the surface of the disk when the disk is not rotating but, when the disk rotates, air is swirled by the rotating disk adjacent a media facing surface, such as an air bearing surface (ABS) of the slider causing the slider to ride on an air bearing a slight distance from the surface of the rotating disk. When the slider rides on the air bearing, the write and read heads are employed for writing magnetic impressions to and reading magnetic signal fields from the rotating disk. The read and write heads are connected to processing circuitry that operates according to a computer program to implement the writing and reading functions.
To write data to the magnetic disk, an electrical current is caused to flow through a conductive coil in the write head to induce a magnetic field across the gap between the main and return poles of the magnetic write head. By reversing the polarity of the current through the coil, the polarity of the data written to the magnetic media is also reversed.
The main pole is generally made of a soft magnetic material that becomes magnetized in a direction perpendicular to the ABS, and generates a magnetic field in the media during recording when the current is applied to the coil. The residual magnetic moment of the main pole when the main pole does not have a write current field from the conductive coil should be close to zero, and the easy axis of the main pole should be oriented along an easy axis parallel to the ABS. When the magnetic moment does not return to an orientation parallel to the ABS, the main pole has a remnant moment with a component perpendicular to the ABS. This remnant magnetic field of the main pole may deteriorate or even erase data from the magnetic medium. To minimize the data erasure, the main pole may be a laminated stack of high moment magnetic layers separated by thin nonmagnetic layers with each layer of the laminated stack forming a part of the main pole at the ABS. However, laminated main pole is known to require higher current to energize and also results in less output compared to an un-laminated main pole.
Therefore, an improved magnetic write head is needed.